Multiple clutch automatic transmission



Feb. 6, 1940. B. A. swENNEs 2,189,537

MULTIPLE CLUTCH AUTOMATIC TRANSMISSION Filed June a, 195s 4 sheets-sheet 1 um, m s

Feb. 6, 1940. B, A SWENNES 2,189,537

MULTIPLE CLUTCH AUTOMATIC TRANSMISSION Filed June 8, 1956 4 Sheets-Sheet 2 MULTIPLE CLUTCH AUTOMATIC TRANSMISSION Filed June 8, 1936 4 Sheets-Sheet 3 Feb. 6, 1940.

B. A. swENNEs' 2,189,537

Filed June e; 195e 4 sheets-sheet 4 Piume Fels. s, i940 MULTIPLE CLUTCH AUTOMATIC TRANSMISSION Benjamin A. Swcnnes, Rockford, lll., assignor to Borg-Warner Corporation, Chicago, Ill., a oorporation of Illinois Application June 8, 1936, Serial No. 84,078

6 Claims.

This invention has to do with an automatic change speed transmission adapted for use upon motor propelled vehicles, and relates particularly to such a transmission having a plurality oi pow- '5 er trains of graduated speed ratio, each having in series therewith an impositiva clutch device increasing in driving eillciency upon an increase in speed, whereby the power trains are brought successively into driving relation between driving and driven transmission shafts.

The primary object of the present invention is the provision in a change speed transmission of an impositiva clutch adapted to establish a substantially one-to-one ratio between driving and driven shafts, a lower ratio power train, and an additional impositive clutch for coupling said shafts through said lower ratio train. By the use of the additional impositive clutch mechanism it is possible to employva low ratio train having a lower ratio providing for greater torque multiplication and increased acceleration of a vehicle to the running gear of which driving power is transmitted through the `transmission device.

The invention as well as the above and other desirable objects will be fully understood upon reading the following description in conjunction with the accompanying four sheets of drawings hereby made a part of the speciiication, and

wherein:

Fig. 1 is a vertical sectional view taken centrally through an automatic transmission mechanism constructed according to the present invention;

Fig. 2 is a fragmentary sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a view taken on the line 3-3 of Fig. 1 and illustrating manually operable control means for a friction clutch;

Flg,'4 is a view similar to Fig. 1, but of a modified form of transmission mechanism; and

Fig. 5 is a. transverse sectional view taken on the line 5-5 of Fig. 4.

The same reference characters are used for designating like parts shown throughout the several figures of the drawings and referred to hereinafter in the description.

'Ihat embodiment of the invention disclosed in Figs. 1, 2 and 3 is contained within a bell housing Ill and a gear box Il, which are suitably connected together. The front or left end of the bell housing l0 may be secured in any standard manner to the crank case of a vehicle engine, not shown. An engine crank shaft l2 has secured thereto by means of bolts I3 a ily-wheel Il, and

(Cl. 'lb-189.5)

the ily-wheel has secured thereto by bolts I5 a clutch casing I6. The fly-wheel I4 may have gear teeth I1 about its periphery for engagement by an engine starting gear, not shown.

Bolts I8 provide means for attaching a clutch 5 cover plate I9 to the back of the clutch casing I6. Said cover plate has a plurality of apertures 20 for receiving spring cups 2 I, of which nine are illustrated in Fig. 3. Within each of the cups 2| is a compression spring 22 bearing between the 10 caps of said cups and an annular pressure plate 23 comprising part of a friction clutch A. Bosses 24 upon the rear face of the pressure plate 23 extend into the forward ends of the springs 22 as a means for holding the springs in place 15 against lateral movement. The pressure plate 23 has three equally spaced lugs 25 extending from its rear face, one of said lugs being plainly shown in Fig. 1. Said lugs extend through apertures 28 in registry therewith in the clutch cover plate I9 20 and adjacent to each aperture 26 there is anchored in the clutch cover plate I9 a fulcrum block 21, Three clutch throw-out fingers 28, which may be of pressed steel, each have a pin 29 engaged in a notch 30 formed in each of the 25 lugs 25. An adjustable fulcrum member 3| in each of the clutch throw-out lingers 28 bears against a lug 21. 'I'he throw-out fingers 28 are held in place by ymeans of springs indicated generally by the reference character 32, said springs 30 being wrapped about oppositeends of the pins 29 and tending to rotate the throw-out ngers 28 counter-clockwise, Fig. 1,' by spring saddle sections 33 bearing against the throw-out fingers and end sections 34 bearing reactively against 35 the clutch cover plate I9. When the radially inward ends of the clutch throw-out lingers are moved forwardly by manual manipulation of a clutch throw-out bearing 35, which is movable axially of the transmission mechanism, said fin- 40 gers will be rotated counter-clockwise, Fig. 1, about an axis coinciding with the point of contact between the members 3i and 21, and whereby the pressure plate 23 is retracted rearwardly of the transmission mechanism against the urge 45 of springs 22.

Contained within the clutch casing I6 is a fluid clutch B. Said clutch consists of a clutch impeller vmember having two parts 36 and 31 secured together about their circular peripheries 50 by a series of bolts 38. The impeller part 31 is secured by rivets 39 to a sleeve 40 which is rotatively disposed upon a shaft section 4I. 'Leakage of uid from the clutch impeller member along the shaft Il is prevented by means of a ring 55 of packing material 42 stuffed within a recess 43 of the sleeve 4.9 where such packing is held compressed by a spring 44 backed by aA 45 snapped into position within a groove 451cm cumscribing the interior of the recess 43. Y

The forward part 36 of the clutch impeller is attached by means of rivets 41 to a flange 48 upon a stub shaft 49 piloted within a. recess 59 formed in the crank shaft |2. Annular clutch facings 5| and 52 are fastened respectively upon the front and rear faces of the clutch impeller.

Within the clutch impeller of clutch B is a clutch driven member or runner 53, the hub 54 of which is connected by means of overrunning clutch rollers 55 to a sleeve 55 which is splined at 51 to the shaft 4|. In Fig. 2, the clutch driven member 53 will be seen to have upon the back dished face thereof a series of radially extending vanes 58 disposed in alternate relation with slightly shorter vanes 59. Each of the vanes 58 and 59 has a. notch 69 which adapt the vanes to receive an annular fluid guide ring 8|. The rear part 31 of the fluid clutch impeller has vanes 62 and G3 corresponding to vanes 58 and 59 of the clutch driven member 53, said vanes 82 and 83 being notched at 54 so that they may receive in opposed relation to the guide member 8| a similar and complemental guide member 55. When the impeller of clutch Bis rotated with respect to the runner 53, fluid within the device is circulated by the vanes 58, 59, 82 and 83, and by the fluid guide rings 5| and 85 in such a manner as to cause the runner 53 to tend t0 follow the movement of the impeller. This tendency of the runner 53 to follow in rotation with the impeller increases with the speed of the impeller, or, stated differently, the power transmitting eiliciency of the impositive clutch device increases as a function of clutch speed.

A bracket 65 secured to the bell housing |9 supports a bearing 61 for rotatively supporting the shaft 4|. The back end of the shaft 4| is connected by pins 68 to the impeller 59 of a fluid clutch C having a structure very similar to clutch B. Parts 19 and 1| are bolted together at 12 about their engaged circular peripheries. The clutch member 1| contains a plugged opening 13 through which oil or other owable substance driving medium may be introduced into the clutch. A similar opening, not shown, is provided in the impeller of clutch B. Within the clutch impeller 89 is a runner 14 having thereon a sleeve hub 15 splined at 18 to a shaft section 11. The runner 14 has vanes 18 and 19 which correspond to the vanes 58 and 59 of the runner 53, and carries a fluid guide ring 89 corresponding to the ring 8| of the runner 53. In opposed relation to the vanes 18 and 19 and the guide ring 89 are corresponding vanes 8| and 82 and a guide ring 83. A ball bearing 88 is disposed between the sleeve hub member 15 and the impeller member 19.

Aligned apertures in the adjacent walls of the bell housing |9 and the gear box support a ball bearing 81 through which extend the shaft 11 and a hollow shaft 88. The hollow shaft 88 is splined at 89 for connection with a hub 99 to which the part 1| of the impeller 59 is attached. Leakage of uid from the clutch C along the shaft 11 is prevented by packing 9| heldin place by a spring 92 similarly to the packing 42 previously described. The rear end of hollow shaft 88 has thereon gear teeth 93 and contains an enlarged bearing 94. Journalled within the bearing 94 is an enlarged section 95 of the shaft In constant mesh with the gear 83 is a gear y 91 having a hub 98 journalled in a bearing 88 within the forward end wall of the gear case Said hub 98 is keyed at |99 to a jack shaft |8| having its back end journalled in a gear case bearing |92. Rota-tively disposed upon the jack shaft |9| is a sleeve |93 having an enlarged forward end section |94 with cam surfaces. not shown, for coacting with overrunning clutch rollers |95 in the conventional manner. A gear cluster |95 is secured non-rotatively to the sleeve |93 and embodies gears |91 and |98.

Within the rear end wall of the gear box is a driven shaft |99 journalled in a ball bearing ||9. Said driven shaft |99 has splined thereto at a coupling member ||2 for attachment to the vehicle torque tube, not shown. The forward end of the driven shaft |99 has a section ||3 of reduced diameter piloted within a bearing ||4 of shaft 11. Splines ||5 upon the driven shaft |99 provide means foi' a non-rotative connection of the gear |I6 thereto. Integral with the gear ||8 is an internal jaw clutch ||1, which may be engaged with the jaw clutch 98 when the gear ||6 and clutch ||1 are shifted forwardly by movement of a manually controlled shifter fork ||8. 'I'he gear ||5 is adapted to be meshed with the gear |91 and the clutch ||1 with the clutch 98 when the shifter fork |98 is pivoted about the axisv of its shaft ||9 to position F. Upon movement of the shifter fork ||8 to position R, the gear ||8 will be shifted axially of the shaft |99 to a position in alignment with the gear |98 where said gear ||5 will be enmeshed with an idler gear, not shown, driven by the gear |98, whereby a reverse rotative movement of the driven shaft |99 is obtained. In Fig. 1, the manually controlled shifter fork |l8 is shown in the neutral position N, thereby positioning the gear ||8 in its neutral position between gears |91 and said idler gear, not shown.

The operation of that form of the invention illustrated in Figs. 1, 2 and 3 will now be described.

When the manually controlled thrust bearing 35 is released, said bearing will permit the springs 22 to force the pressure ring 23 forwardly, whereby the clutch faclngs 5| and 52 upon opposite sides of the clutch impeller of clutch B are gripped between the front face of the pressure ring 23 and the rear face of the fly-wheel I4. With the impeller member of clutch B thus connected with the vehicle engine, said engine may be rotated at idling speed without imparting to the clutch driven element 53 enough torque to cause movement of the vehicle. Incident, however, to an increase in speed of the vehicle engine more and more torquewill be imparted to the driven element 53, and torque will then be transmitted through the overrunning clutch rollers 55 and splined sleeve 55 to the shaft 4|\, and thence to the impeller 89 of clutch C, then to hollow shaft 88, gear 93, gear 91, overrunning clutch rollers |95, sleeve |93, and gears |91 and |I8 (when the shifter fork ||8 is in position F) to the driven shaft |99. A reduced speed of the driven shaft |99 is obtained both through the slippage between the driving and driven parts of clutch A and through the reduction gearing in the gear box I, such gearing providing a mechanical advantage or multiplication of engine driving torque.

As the vehicle proceeds in the forward direction and the speed of clutch B increases, the

theretoaiiy-wheslu'disposedinthcforward.

driving emciency or said clutch likewise increales, sothatthe'speedofthedrivenelementmon nearly approaches the speed of the impellor. Likewise, the speed of the impcller Il of clutch C increases and the torque imparted to the runner 14 increases. -After a predetermined speed of the clutch impeller has been reached, liroviding a normal load remains on the driven shaft |00, the torque delivered through the iluid medium in clutch C to the runner 14 will be ade-r quate to carry the vehicle load. When this condition of torque delivery prevails, power will be transmitted directly from the engine through clutches A and B, shaft 4|, clutch impeller 00, clutch runner 14, shaft 11, jaw clutch elements 00 and ||1 to the driven sh ft |00. At this time, the slip between the impos tive clutch impellers and their respective runners 53 and 14 will be very slight, so that the driven shaft |00 will be caused to rotate at substantially the same speed as the crank shaft I2. Meanwhile, the gear ||0 whichremains in mesh with the gear |01 will cause the sleeve head |04 to rotate faster than the gear 01 as is permitted by the clutch rollers |05.

Were the crank shaft I2 connected directly to the impeller 69 instead of being connected thereto through the impositive clutch B, the impeller 69 would, at a lower engine speed, be caused to rotate at a speed adequate to give to the clutch C a driving efficiency capable of establishing the substantial one-to-one driving ratio between the crank shaft I2 and the driven shaft |09. It will be conceived thatif the substantially one-to-one driving ratio power train is established between shafts l2 and |09 while the vehicle engine is rotating at a speed below that at which it operates to develop its maximum torque, the rate of acceleration of the vehicle will not be the maximum obtainable. This unhappy condition may be overcome by increasing the speed ratio of the gears which are interposed in the low speed power train, but only by creating another disadvantage, namely, that of giving to the transmission mechanism a starting power train of too high a ratio for rapid acceleration upon the car being started from rest. With the present device a very low ratio gear train may be used, but the transfer of torque from the driving member to the higher ratio train is delayed until the engine has attained sufficient speed to develop the torque required to accelerate and carry the load through the higher ratio train. v

It will be noted that when the shifter fork ||8 is in the position N, the jaw clutch element ||1 is out of mesh with the clutch element 96 as well as the gear I6 being disconnected from a source of driving power. It is, therefore, impossible for the driven shaft |09 to receive driving force from either the direct drive power train including the shaft 11 or through the low speed ratio power train including the gear |01.

When the yoke |18 occupies the position R, the driven shaft |09 can be driven only through the speed reduction gearing inasmuch as the connection between clutch elements 96 and |1 remains broken.

In the following description of that form of the invention shown in Figs. 4 and 5, parts corresponding to those shown in Figs. 1, 2 and 3 will be indicated by the same reference character, but with the addition of a prime. Referring first to Fig. 4, the transmission will be seen as driven from a crank shaft I2' having attached end of sbellhousing I0'. Them-wheel |4' has attached to its rear face a clutch casing I4.

An automatic friction clutch D is employed forconnectingthecrankshaft |2toatransmission shaft 20|. The clutch D inludes a pressure ring 23 which is adapted to compress therebetween and the back of the ily-wheel I4 clutch facings and 52 which are secured upon opposite sides of a driven clutch disk The friction clutch disk 20| has-a hub 202 splined at 200 to the shaft 200. Disposed equi-angularly about the back side of the clutch cover IB' are three U-shaped brackets 205 between the legs of which are secured levers 208 by, means of pivot pins 201; see Figs. 4 and 5. Centrifugal weights 208 are pivoted at 209 to lugs 200l upon the clutch cover plate I0. The weights upon each pair of lugs 200 have disposed therebetween cross pieces 2|0 which add to the centrifugal mass of the weights 208 and to the rigidity of their interfabrication. Paired links 2|| form a connection between an end of each lever 200 and the weights 208 in radial alignment therewith. The links 2| are pivotally connected with thelevers r20B and with their respective weights, the connection with the weights being at a point selectively spaced from their point of pivotal anchorage. A compression spring 2|2 is placed between each lug 2|3. secured to the clutch cover plate I6 adjacent eac-h pair of lugs 209, and the end of the lever 206 opposed thereto. Telescopically connected guide pins 2|4 and 2|5 connected respectively to the lugs 2|3 and to coupling members 2|6, which are disposed between the levers 206 and the links 2| serve as retaining means for the springs 2| 2.

Upon the ends of the levers 206 opposite to that to which the links 2| are coupled are journalled rollers 2|1. The rollers 2|1 are arranged for exerting pressure against a flange 2|9 turned radially outwardly from' a sleeve 220 which is slidable axially of the transmission device. At this time, it should be noted that the levers 206 are designed to -multiply the force of the springs 2|2 as applied to the sleeve flange 2|9.

Arranged alternately with the centrifugal mechanisms just described on the back of the clutch casing I6 are three openings 26. Three bosses 25' extending rearwardly from the pressure plate 23 project through the openings 26'. Pivotally connected with each of the bosses 25' by means of pins 29 are clutch throw-out fingers 28.` Adjustable fulcrum members 3| abut against the fulcrum blocks 21', and the inner ends of the fingers 28 are connected to the slidable sleeve 220 by means of links 22|. The links 22| are secured to their respective levers 28 by means of pins 222 and to the sleeve 220 by means of pins 223 anchored in ears 224 projecting radially from the sleeve 220. Spring devices 225 and 226 mounted respectively upon pins 29 and 223 bear against levers 28 and links 22| to prevent rattling of such levers and links during operation of the transmission.

Six spring cups or seats 2 are arranged about the back side of the clutch casing I6' in alternate relation with the centrifugal devices and the levers 28'. Strong compression springs 22', Fig. 4, have an end confined within the cups 2|' and an opposite end bearing against the back of the pressure plate 23. Thus, it will be seen that the spring 22' vat all times urge the pressure ring 23' forwardly into a position in engagement with the friction element 52'. The springs 2|2 radially outwardly to compress the springs 2|2, which normallyoppose and overbalance the force of the springs 22'. Outward movement of thelinks 2|| concurrently with the compression of the springs 2|2 and counter-clockwiseI pivotal movement of the levers 206, Fig..4,'permits the springs 22' to force the pressure plate `23' forwardly, meanwhile pivoting the levers 28' in a clockwise direction, and shifting the sleeve 220 rearwardly. The force exerted by the pressure plate 23' against the friction element 52' moves the clutch driven element 2|6 slightly forwardly to concurrently effect an engagement between the friction element 5I andthe ily-wheel I4. Thus, by increasing the speed of the vehicle engine above idling speed, the shaft 206 may be connected directly to the crank shaft |2'. l

A dividing wall 221 in the housing |0' is suitably apertured for containing a ball bearing/226 which rotatively supports the backend of the shaft 206. 'Ihe forward end of the shaft`266 is having parts 236 and 23| secured together by a plurality of bolts 232. The part 230 is secured in any suitable manner to the back end of the shaft 266, whereas the part 23| is journalled by means of a ball bearing 233 'upon a' shaft 234. Splined at 235 to the'shaftv234is the hub 236 of a clutch runner 231. A ball bearing 238 permits of relative rotation between the impeller part 236 and the hub 236. Upon the interior of the impeller part 23| are fluid impelling vanes 236 and 246 which carry a fluid guide ring 24|. The nmner 231 has fluid impelled vanes 242 and 243 which carry a fluid guide ring 244. Clutch E and the vanes and iluid guide ringstherein are of similar structure as those previouslyv der scribed in connection with clutchesv B and C.

at 25| t0 a 4shaft 252 and a ball bearing 253 is disposed between `the forward part of the impeller 241 and the hub of the runner 256. It will be noted 'from the drawing that the impeller 241 and the clutch driven element 256 each contain fluid impelling and impelled vanes and .fluid directing rings corresponding to those shown in clutches B, C and E. The rear section of the impeller 241 is connected bypins 254 to a hollow shaft 255. Such shaft 25.5 encloses the shaft 252 and is itself enclosed within a hollow shaft 2n, which is journaued within a banbearmg 251 disposed within the rear end `wall of the housing I6'. all project into the gear box I'. l

Connection is had betweenthe shaft 256 and the impeller 223* of the clutch E by means of a cylindrical member 251B of a large diameter adapting itto contain the clutch F, said cylinshaft 25s.

The back` ends of shafts'252, 255 and 256 rit-256 and 266 in the two ends of the'gear box A gear 260* co-'axial with the countershaft IUI' is in constant mesh withV gear teeth .26| cut within the rear end of the` shaft 256.

Ag'ear262 of less diameter than the gear 266* meshes with gearV teeth 263 upon the hollow Gears 260* and 262 are connected, respectively, by overrunning clutch rollers 264 rand 265. Cam rings 266 and 261 provide a connection between the clutch rollers 264 -and 265 and the splined shaft A collar 266 maintains a selected spacing between cam rings 266 and 261, whereas the spacing between the cam ring member 261 and a gear cluster |06 is maintained by a collar 269. Gears |61' and |08' are formed upon the. cluster gear element.

'I'he gear ||6 splined upon the driven shaft |06 is shiftable into any one of four positions corresponding to positions R, N, F and F2 of the manually actuable shifter fork H8. Shifter fork H6' is illustrated in position F, whereby the transmission mechanism is arranged for driving the vehicle in the forward direction. In this position of the fork H8 the gear H6 is meshed with gear |61' and jaw clutch |I1' is interlocked with jaw clutch element 66.

Operation of that form of the invention shown in Figs. 4 and 5 will now be described.

The device is capable of providing power trains of three different speed ratios between the propeller shaft |2 and the driven shaft |69. While the engine is standing idle or is rotating at a speed not in excess of engine idling speed, the centrifugal weights 266 of clutch D will be in the position shown in Fig. 4. Springs 2| 2, therefore. will be permitted to predominate over springs 22 and clutch D will remain unengaged.

Upon increasing the speed of the engine above idling speed, the weights 266 will be thrown centrifugally outwardly, whereby the springs 22' become effective for closing clutch D in the manner hereinabove described, and whereupon the crank shaft I2 becomes connected to the shaft 266. This connection having been made between shafts |2 and 266, a power train of low speed ratio will have been established between the shaft l2 and the driven shaft |66', said power train including in addition to the clutch D and the shaft 266, the impeller 229' of clutch E, cylinder 251', disk 256, hollow shaft 256, gear 26|, gear 266, clutch rollers 264, jack shaft |6|', gear |61' and the gear H6'. A speed reduction and torque multiplication is obtained through the gears 26|, 266', |61 and ||6'. While the vehicle is being propelled forwardly by means of the power train just described, the clutch impeller 223l of clutch E will be rotating at a speed in excess of that of the runner '231. However, upon sumcient increase in speed of the impeller 226", more and more vtorque will be transmitted to the impeller 231 until finally such torque is sumcient to drive the driven shaft |66' through a power train of higher or intermediate speed ratio. The intermediate-speed ratio train includes the clutch D, shaft 266, impeller 223, clutch runner 231, shaft 234, clutch impeller 241, hollow shaft 255, gear 263, gear 262, clutch rollers 265, cam ring member 261, jack shaft Ill and gears |61' and II6'.

While the Shaft |66 is being driven at thehigher u speed through the intermediate ratio train, the cam ring member 286 will be rotated at a speed in excess and in the same direction as the gear 280e, but the clutch rollers 2M permit the cam ring 268 to thus overrun theV gear 260..

Direct drive is established between the shafts i I2' and |09' after the vehicle has attained a speed at which the clutch impeller 241 is rotating at a speed suiiicient lto trans/ndt a driving torque to the runner 250 adequate to carry the vehicle load. The third speed or direct driving power train includes in serial relation the clutch D, shaft 200, impeller 229, runner 231, shaft 224, impeller 241, runner 250, shaft 252, jaw clutches 06 and Ill and the body of the gear IIB' which is splined to the shaft |08'. During direct drive of the shaft |09', the jack shaft Ill will be driven at a speed in excess of both gears 280n and 282 as permitted by clutch rollers 264 and 'I'he double impositive clutch arrangement shown in Fig. 4 accomplishes the same objective as the double clutchl arrangement shown and described in' connection with that form of the device shown in Figs. 1, l2 and 3; that is, the impositive clutch E permits of th use of a power train of a selected speed' reduction ratio to be interposed between the impeller thereof and the driven shaft |09', while adapting the vehicle engine to rotate at a sufiiciently high speed before driving torque is diverted in a substantial amount through the so-called direct drive power train.

When it is desired that the vehicle shall be driven in the lower speed ratio power trains without automatically changing into the high speed power train, the shifter fork IIB' will be moved into position F", so thatthe :law clutchv in the neutral position is accomplished by shift` ing the fork H8 into position N so that the jaw clutches 96 and H1 are disconnected as well y as the gears H6' and |01'. The gear H6 will then be disposed in the space between the gears E01 and |08'.

Reverse drive of the shaft |09 may be had by shifting the fork i I8' into position R and thus sliding the gear H6 rearwardly into alignment with the gear |08 into mesh with an idler gear, not shown, driven from the gear |08. It will be noted that' the shaft |09 may be reversely driven either through the low or intermediate speed power trains, but not through the direct drive train.

I claim:

1'. A change-speed transmission comprising driving and driven members, anda speed-responsive mechanical clutch, driven from the driving member, a plurality of uid clutches and a plurality of gear trains of different speed ratios adapted to be connected between the mechanical clutch and driven member, said fluid clutches comprising an impeller driven directly 'from the mechanical clutch, a runner adapted to be driven from the impeller, a second impeller secured to Aresponsive friction clutch driven from said driving the runner for rotation therewith, and a second runner cooperating with said second impeller, means for connecting the iirst impeller to a gear train, means for connecting the second impeller to another gear train, means for connecting the 5 second runner to the driven member, and overrunning clutches in each of the gear trains, whereby said driven member can be made to increase in speed automatically from a condition of rest to a condition of synchronism with the driving member while said driving member is rotating within a small range of speeds.

2. An automatic change-speed transmission comprising driving and driven members, a speed- 15 member and becoming effective to transmit torque therefrom upon the driving member attaining a predetermined speed, and means for bringing the driven member up to the speed of the driving member from a lcondition of rest, said means comprising slippable fluid clutches in series with one another, and gear trains of different speed ratios, the impeller of one of said uid clutches being driven directly from the friction clutch and in series with the lowest speed ratio train, a runner cooperating with said impeller, a second impeller secured to said runner for rotation therewith, said second impeller being in series with the next lowest speed ratio train, a runner cooperating with the second impeller, overrunning clutches in series with said trains, and a direct connection between the second runner and the driven member, whereby said driven member, upon a sumcient increase in speed of the driving member to operate the friction clutch, is first driven through the `iirst impeller and lowest ratio gear train, then through the flrst'runner and associated second impeller and second lowest ratio gear train while overrunning the clutch in the iirst gear train, and iinally through the second runner and direct connection while overrunning both clutches.

3. An automatic change-speed transmission comprising driving and driven members, a friction clutch in series with the driving member and adapted to be operative only upon the driving member attaining a predetermined speed, and means intermediate the clutch and driven member for bringing said driven members up to the. speed of said driving member, said means comprising an impeller, a low ratio gear train and an overrunning clutch, all in series with the driven member, a runner cooperatively related to the impeller, a second impeller, a gear train of higher speed ratio and an overrunning clutch, said runner, second impeller and higher ratio train also being in series with the driven member, and a runner'cooperatively related to the second im-v peller and directly connected to the driven member, whereby said driven member upon an operation of the first mentioned clutch, is driven from the iirst impeller and lowest speed ratio train, then from the first runner and gear train of higher speed ratio While overrunning the firstmentioned overrunning clutch and then from' thesecond runner at substantially the speed of the driving member, while overrunning both of said overrunning clutches. A

4. An automatic change-speed transmission comprising driving and driven members, a fric tion clutch in series with the driving and driven members and adapted to be operative only upon the driving member attaining a predetermined speed, and means for bringing said driven member up to the speed of the driving member, said n means comprising an impeller driven i'rom said clutch, a runner cooperatively related to said impeller and adapted to transmit torque therefrom upon an increase in speed of said impeller, a sec ond impeller drivingly connected to said runner, a gear train of low speed ratio and anoverrunning clutch in series with said impeller and said driving member, and a runner cooperatively related to said second impeller and adapted to be drivingly connected to the driven member, whereby no torque is transmitted to the driven member while the driving member is rotated below a predetermined speed, but upon an increase in speed, said iirst mentioned clutch is rst operated, then the first mentioned runner and second impeller are rotated, thereby driving the driven member and increasing its speed until the speed of the driving member is attained, whereupon said second runner drives the driven member while overrunning said overrunning clutch.

5. An automatic change speed transmission comprising driving and driven members, a speed responsive friction clutch for transmitting torque from the driving member to the driven member, a plurality of power trains of diierent speed ratios adapted to be connected between the friction clutch and driven member, and a plurality of fluid clutches in series with one another and with the highest speed ratio train, one of said clutches being in parallel with another power train, said fluid clutches being successively operable and thereb'y serving to delay the transmission of torque from the driving member to the driven member through the highest speed ratio train until the drivenmember is rotating at a speed within the range of speed at which the driving member is designed to be most eiiicient. 6. A change speed transmission comprising driving and driven members, a plurality of power trains of graduated mechanical advantage establishable in driving relation between said members, one way drive means in series with each of said power trains excepting the one of least mechanical advantage, and means for establishing said trains in such driving relation comprising clutchmeans eective to establish the driving relation of the train of greatest mechanical advantage incident to an increase in speed oi the driving member, and a plurality of clutch devices including driving and 4driven elements adaptedlto increase in driving efnciency upon an increase in rotative speed of their respective driving elements, there being one of said devices in each power train except the train o! greatest mechanical advantage, and the driving element of said devices being driven by the train of next greater mechanical advantage, each of said one way drive means operating to prevent the transmission of torque from the driven member of the clutch of its power train to the driving member of said clutch when the train of next lower mechanical advantage is made effective.

BENJAMIN A. SWENNES. 

